An endangered southern pudu, the world's smallest deer, is seen at The Wildlife Conservation Society's Queens Zoo in New York

An endangered southern pudu, the world's smallest deer, is seen at The Wildlife Conservation Society's Queens Zoo in New York

SHANNON STAPLETON / Reuters

An endangered southern pudu, the world's smallest deer, is seen at The Wildlife Conservation Society's Queens Zoo in New York The southern pudu doe, which is native to Chile and Argentina, was born at the zoo weighing one pound and could weigh as much as 20 pounds as an adult.

An endangered southern pudu, the world's smallest deer, is seen at The Wildlife Conservation Society's Queens Zoo in New York The southern pudu doe, which is native to Chile and Argentina, was born at the zoo weighing one pound and could weigh as much as 20 pounds as an adult. (SHANNON STAPLETON / Reuters)

An endangered southern pudu, the world's smallest deer, is seen at The Wildlife Conservation Society's Queens Zoo in New York The southern pudu doe, which is native to Chile and Argentina, was born at the zoo weighing one pound and could weigh as much as 20 pounds as an adult.